Many types of input devices are presently available for performing operations in a computing system, such as buttons or keys, mice, trackballs, joysticks, touch sensor panels, touch screens and the like. Touch sensitive devices, such as touch screens, in particular, are becoming increasingly popular because of their ease and versatility of operation as well as their declining price. A touch sensitive device can include a touch sensor panel, which can be a clear panel with a touch-sensitive surface, and, in some cases, a display device such as a liquid crystal display (LCD) that can be positioned partially or fully behind the panel so that the touch-sensitive surface can cover at least a portion of the viewable area of the display device. The touch sensitive device can allow a user to perform various functions by touching the touch sensor panel using a finger, stylus or other object at a desired location and, in the case of the display device, at a location often dictated by a user interface (UI) being displayed by the display device. In general, the touch sensitive device can recognize a touch or hover event and the position of the event at the touch sensor panel, and the computing system can then interpret the event and thereafter can perform one or more actions based on the event.
In addition to a touch sensor panel, some touch sensitive devices can include a button, which when contacted by a user can cause the device to change a state associated with the button. Pressing or selecting the button can activate or deactivate some state of the device. Not pressing or selecting the button can leave the device in its current state. In general, the touch sensitive device can recognize a press or force event at the button, and the computing system can then interpret the event and thereafter can perform one or more actions based on the event.
The use of multiple input mechanisms, such as a touch sensor panel and a button, can provide additional functionality for the user. On the other hand, each mechanism requires circuitry space and operating power, which can undesirably increase device size and decrease battery life.